We use the word `duffer’ nowadays to refer to someone who is stupid or someone who is very bad at doing something. The word is considered to be rather old fashioned.
*Reema told me that Ganesh was a duffer at football.*Please, not Sita! I don’t want that duffer in my team.
When the word was first used, it had nothing to do with people who had little or no intelligence. In fact, the original duffer was someone who sold spurious goods. He was a cheat, a no good peddler of very low morals. With the passage of time, however, the meaning `no good’ shifted from the seller to the naïve buyer. He was `no good’ because he was stupid enough to be easily tricked into buying something questionable. In the late 19th Century, the word began to be used to refer to someone who was really bad at golf!